Technical Field
The present disclosure relates to a probe card.
Description of Related Art
The main purpose of a probe card is to achieve automated measurement by directly contacting the probes to the pads or bumps on the DUTs (Device Under Test, such as a chip) and coordinating with peripheral testing machines and software controlling. Therefore, the electrical characteristics and performances of the DUTs can be ensured to comply with the design specifications, and defective products can be effectively screened. The actual testing procedures generally are transmitting testing signals from the testing machines to the DUTs through the probe card, and returning the testing results from the DUTs to the testing machines through the probe card to be further analyzed.
The probe card has precise contacting mechanisms for performing electrical tests to the circuits on the DUTs, and the precise contacting mechanisms are probes. In general, the high temperature setting of circuit probing test is usually more than 80° C., and the chuck emits thermal radiation, which therefore affects metal behavior in the space near the chuck. For example, the lengths of the affected probes will increase, so as to affect the three-dimensional positions of the needle tips.
However, the thermal stream of the thermal radiation is actually dynamic, so the probes may face different thermal energy impacts, which results in that the three-dimensional positions of the needle tips cannot be determined and further causes a large difference between probe marks respectively at room temperature and a high temperature. The above situations become serious especially to the probe cards having large probing areas, such as multi-DUT probe cards. When the location of the probe mark is not precise, some probes may not precisely contact the pads or bumps on the DUT when testing, which will seriously affect the electrical detection functions of the probe card. Because the foregoing deviation problem of offset of the probe marks occurs frequently, it tends to increase the length of debugging time and setting multi-DUT probe markings.